From the Guidelines
Echocardiography findings in pulmonary embolism typically include right ventricular dysfunction and dilation, with key findings being right ventricular dilation, hypokinesis, paradoxical septal motion, tricuspid regurgitation, pulmonary hypertension, McConnell's sign, and the 60/60 sign. These findings are due to increased right ventricular afterload caused by the pulmonary embolism obstructing blood flow in the pulmonary arteries, leading to right ventricular strain and dysfunction 1. Key echo findings to look for in suspected pulmonary embolism include:
- Right ventricular dilation: The right ventricle appears enlarged compared to the left ventricle.
- Right ventricular hypokinesis: Reduced movement of the right ventricular free wall.
- Paradoxical septal motion: The interventricular septum moves abnormally towards the left ventricle.
- Tricuspid regurgitation: Increased blood flow backwards through the tricuspid valve.
- Pulmonary hypertension: Elevated pulmonary artery pressure.
- McConnell's sign: Hypokinesis of the right ventricular free wall with normal apical contractility.
- 60/60 sign: Right ventricular acceleration time <60 ms with tricuspid regurgitation pressure gradient <60 mmHg. However, it's essential to note that a normal echocardiogram does not rule out pulmonary embolism, especially in hemodynamically stable patients 1. Echo findings are most useful in risk stratification and guiding management decisions in confirmed cases of pulmonary embolism, as they can help identify patients with high-risk features, such as right ventricular dysfunction, which is associated with increased mortality 1. In patients with suspected pulmonary embolism, echocardiography can also help identify alternative diagnoses, such as pericardial tamponade, acute valvular dysfunction, or hypovolemia 1. Overall, echocardiography is a valuable tool in the diagnosis and management of pulmonary embolism, but its findings should be interpreted in the context of clinical presentation and other diagnostic tests 1.
From the Research
Echocardiogram Findings in Pulmonary Embolism
The echocardiogram findings in pulmonary embolism (PE) include:
- Increased right ventricle: left ventricle size ratio 2
- Abnormal septal motion 2, 3
- McConnell's sign 2, 3
- Tricuspid regurgitation 2
- Elevated pulmonary artery systolic pressure 2, 4
- Decreased tricuspid annular plane systolic excursion 2, 5
- Decreased S' 2
- Pulmonary artery mid-systolic notching 2
- 60/60 sign 2
- Speckle tracking demonstrating decreased right ventricular free wall strain 2
- Right ventricular dilatation 6, 3, 4
- Right ventricular hypokinesis 6, 3
- Paradoxical septal motion 3
- Right ventricular dysfunction 6, 3, 4
- Elevated pulmonary arterial pressures 4
- Right ventricular hypertrophy 4
- Left ventricular impaired relaxation 4
Diagnostic Utility of Echocardiography
Echocardiography is useful for identifying patients with pulmonary embolism who may have a poor prognosis 6, and for rapid and accurate risk assessment 6. It can also be used to monitor the effect of treatment and judge whether the selected management strategy is successful 6. The diagnostic performance of right ventricular dilatation identified by emergency physicians on bedside echocardiography has been studied, with a sensitivity of 50% and a specificity of 98% 3.
Risk Stratification
Echocardiography plays a role in risk stratification at the time of diagnosis 5, and can help identify patients at risk for death or recurrent thromboembolism 6. Patients with acute PE who have echocardiographic evidence of right ventricular dilatation and/or right ventricular dysfunction have a worse prognosis 4.